16 resultados para adhesin
em Biblioteca Digital da Produção Intelectual da Universidade de São Paulo
Resumo:
Pathogenic strains of Escherichia coli are the most common bacteria associated with urinary tract infections in both humans and companion animals. Standard biochemical tests may be useful in demonstrating detailed phenotypical characteristics of these strains. Thirteen strains of E. coli isolated from dogs with UTIs were submitted to biochemical tests, serotyping for O and H antigens and antimicrobial resistance testing. Furthermore, the presence of papC, sfa, and afa genes was evaluated by PCR, and genetic relationships were established using enterobacterial repetitive intergenic consensus PCR (ERIC-PCR). The antimicrobial that showed the highest resistance rate among the isolates was nalidixic acid (76.9%), followed by cephalotin (69.2%), sulfamethoxazole + trimethoprim (61.5%), tetracycline (61.5%), streptomycin (53.8%), ciprofloxacin (53.8%), ampicillin (46.2%), gentamicin (30.8%) and chloramphenicol (23.1%). No isolate was resistant either to meropenem or nitrofurantoin. Among the five clusters that were identified using ERIC-PCR, one cluster (A) had only one strain, which belonged to a serotype with zoonotic potential (O6:H31) and showed the genes papC+, sfa+, afa-. Strains with the genes papC-, sfa+, afa- were found in two other clusters (C and D), whereas all strains in clusters B and E possessed papC-, sfa-, afa- genes. Sucrose and raffinose phenotypic tests showed some ability in discriminating clusters A, B and C from clusters D and E.
Resumo:
Pathogenic Leptospira is the etiological agent of leptospirosis, a life-threatening disease that affects populations worldwide. Surface proteins have the potential to promote several activities, including adhesion. This work aimed to study the leptospiral coding sequence (CDS) LIC11087, genome annotated as hypothetical outer membrane protein. The LIC11087 gene was cloned and expressed in Escherichia coil BL21 (DE3) strain by using the expression vector pAE. The recombinant protein tagged with N-terminal 6XHis was purified by metal-charged chromatography and characterized by circular dichroism (CD) spectroscopy. The recombinant protein has the ability to mediate attachment to the extracellular matrix (ECM) components, laminin and plasma fibronectin, and was named Lsa30 (Leptospiral surface adhesin of 30 kDa). Lsa30 binds to laminin and to plasma fibronectin in a dose-dependent and saturable manner, with dissociation equilibrium constants (K-D) of 292 +/- 24 nM and 157 +/- 35 nM, respectively. Moreover, the Lsa30 is a plasminogen (PLC) receptor, capable of generating plasmin, in the presence of activator. This protein may interfere with the complement cascade by interacting with C4bp regulator. The Lsa30 is probably a new surface protein of Leptospira as revealed by immunofluorescence assays with living organisms and the reactivity with antibodies present in serum samples of experimentally infected hamsters. Thus, Lsa30 is a novel versatile protein that may play a role in mediating adhesion and may help pathogenic Leptospira to overcome tissue barriers and to escape the immune system. (C) 2012 Elsevier Ltd. All rights reserved.
Resumo:
Pathogenic strains of Escherichia coli are the most common bacteria associated with urinary tract infections in both humans and companion animals. Standard biochemical tests may be useful in demonstrating detailed phenotypical characteristics of these strains. Thirteen strains of E. coli isolated from dogs with UTIs were submitted to biochemical tests, serotyping for O and H antigens and antimicrobial resistance testing. Furthermore, the presence of papC, sfa, and afa genes was evaluated by PCR, and genetic relationships were established using enterobacterial repetitive intergenic consensus PCR (ERIC-PCR). The antimicrobial that showed the highest resistance rate among the isolates was nalidixic acid (76.9%), followed by cephalotin (69.2%), sulfamethoxazole + trimethoprim (61.5%), tetracycline (61.5%), streptomycin (53.8%), ciprofloxacin (53.8%), ampicillin (46.2%), gentamicin (30.8%) and chloramphenicol (23.1%). No isolate was resistant either to meropenem or nitrofurantoin. Among the five clusters that were identified using ERIC-PCR, one cluster (A) had only one strain, which belonged to a serotype with zoonotic potential (O6:H31) and showed the genes papC+, sfa+, afa-. Strains with the genes papC-, sfa+, afa- were found in two other clusters (C and D), whereas all strains in clusters B and E possessed papC-, sfa-, afa- genes. Sucrose and raffinose phenotypic tests showed some ability in discriminating clusters A, B and C from clusters D and E.
Resumo:
Paracoccidoides brasiliensis adhesion to lung epithelial cells is considered an essential event for the establishment of infection and different proteins participate in this process. One of these proteins is a 30 kDa adhesin, pI 4.9 that was described as a laminin ligand in previous studies, and it was more highly expressed in more virulent P. brasiliensis isolates. This protein may contribute to the virulence of this important fungal pathogen. Using Edman degradation and mass spectrometry analysis, this 30 kDa adhesin was identified as a 14-3-3 protein. These proteins are a conserved group of small acidic proteins involved in a variety of processes in eukaryotic organisms. However, the exact function of these proteins in some processes remains unknown. Thus, the goal of the present study was to characterize the role of this protein during the interaction between the fungus and its host. To achieve this goal, we cloned, expressed the 14-3-3 protein in a heterologous system and determined its subcellular localization in in vitro and in vivo infection models. Immunocytochemical analysis revealed the ubiquitous distribution of this protein in the yeast form of P. brasiliensis, with some concentration in the cytoplasm. Additionally, this 14-3-3 protein was also present in P. brasiliensis cells at the sites of infection in C57BL/6 mice intratracheally infected with P. brasiliensis yeast cells for 72 h (acute infections) and 30 days (chronic infection). An apparent increase in the levels of the 14-3-3 protein in the cell wall of the fungus was also noted during the interaction between P. brasiliensis and A549 cells, suggesting that this protein may be involved in host-parasite interactions, since inhibition assays with the protein and this antibody decreased P. brasiliensis adhesion to A549 epithelial cells. Our data may lead to a better understanding of P. brasiliensis interactions with host tissues and paracoccidioidomycosis pathogenesis.
Resumo:
There is growing evidence that the course of Bipolar Affective Disorder (BAD) can be altered by psychotherapeutic approaches, such as Psychoeducation. Therefore, this study was performed with the objective of identifying the implications of a Psychoeducation group on the everyday lives of individuals with BAD. To do this, the authors chose to perform a qualitative case study. Participants included twelve individuals with BAD who had attended at least six meetings of the Psychoeducation Group held at the Sao Jose do Rio Preto Faculty of Medicine (FAMERP). Semi-structured interviews were performed, which were recorded and then transcribed and subjected to Thematic Analysis. The present study showed that the referred group experience promoted the individuals' knowledge acquisition; their awareness regarding the disease and adherence to treatment; their making positive changes in life; the possibility of helping other patients to benefit from the knowledge learned in the group; and their awareness regarding other realities and coping strategies, obtained by exchanging experiences with other participants.
Resumo:
LigB is an adhesin from pathogenic Leptospira that is able to bind to extracellular matrix and is considered a virulence factor. A shotgun phage display genomic library was constructed and used for panning against Heparan Sulfate Proteoglycan (HSPG). A phage clone encoding part of LigB protein was selected in panning experiments and showed specific binding to heparin. To validate the selected clone, fragments of LigB were produced as recombinant proteins and showed affinity to heparin and to mammalian cells. Heparin was also able to reduce the binding of rLB-Ct to mammalian cells. Our data suggests that the glycosaminoglycan moiety of the HSPG is responsible for its binding and could mediate the attachment of the recombinant protein rLB-Ct. Thus, heparin may act as a receptor for Leptospira to colonize and to invade the host tissue. (C) 2012 Elsevier Inc. All rights reserved.
Resumo:
Objetivou-se analisar potencialidades e limites da estratégia do tratamento supervisionado (DOTS) para a tuberculose, sob a percepção de usuários em tratamento e de trabalhadores de saúde de uma supervisão técnica de saúde do município de São Paulo. Entrevistaram-se 4 usuários e 17 profissionais de saúde de nove unidades básicas de saúde, entre abril e junho de 2006, após consentimento livre e esclarecido. Os depoimentos foram decodificados segundo a técnica de análise de discurso. Adotou-se a teoria da determinação social do processo saúde/doença como referencial teórico. Foram potencialidades: criação de vínculo entre profissional/usuário e incentivos ao tratamento, o que favorece a adesão. Foram limites: restrito envolvimento dos profissionais no DOTS e conciliar horário de trabalho do usuário com a supervisão. Reitera-se que a adesão ao tratamento transcende o âmbito biológico, sendo fundamental que os trabalhadores de saúde reconheçam os usuários como portadores de necessidades, não se restringindo apenas à supervisão da tomada de medicamentos.
Features of two proteins of Leptospira interrogans with potential role in host-pathogen interactions
Resumo:
Background: Leptospirosis is considered a re-emerging infectious disease caused by pathogenic spirochaetes of the genus Leptospira. Pathogenic leptospires have the ability to survive and disseminate to multiple organs after penetrating the host. Leptospires were shown to express surface proteins that interact with the extracellular matrix (ECM) and to plasminogen (PLG). This study examined the interaction of two putative leptospiral proteins with laminin, collagen Type I, collagen Type IV, cellular fibronectin, plasma fibronectin, PLG, factor H and C4bp. Results: We show that two leptospiral proteins encoded by LIC11834 and LIC12253 genes interact with laminin in a dose - dependent and saturable mode, with dissociation equilibrium constants (K-D) of 367.5 and 415.4 nM, respectively. These proteins were named Lsa33 and Lsa25 (Leptospiral surface adhesin) for LIC11834 and LIC12253, respectively. Metaperiodate - treated laminin reduced Lsa25 - laminin interaction, suggesting that sugar moieties of this ligand participate in this interaction. The Lsa33 is also PLG - binding receptor, with a K-D of 23.53 nM, capable of generating plasmin in the presence of an activator. Although in a weak manner, both proteins interact with C4bp, a regulator of complement classical route. In silico analysis together with proteinase K and immunoflorescence data suggest that these proteins might be surface exposed. Moreover, the recombinant proteins partially inhibited leptospiral adherence to immobilized laminin and PLG. Conclusions: We believe that these multifunctional proteins have the potential to participate in the interaction of leptospires to hosts by mediating adhesion and by helping the bacteria to escape the immune system and to overcome tissue barriers. To our knowledge, Lsa33 is the first leptospiral protein described to date with the capability of binding laminin, PLG and C4bp in vitro.
Resumo:
TSSA (trypomastigote small surface antigen) is a polymorphic mucin-like molecule displayed on the surface of Trypanosoma cruzi trypomastigote forms. To evaluate its functional properties, we undertook comparative biochemical and genetic approaches on isoforms present in parasite stocks from extant evolutionary lineages (CL Brener and Sylvio X-10). We show that CL Brener TSSA, but not the Sylvio X-10 counterpart, exhibits dose-dependent and saturable binding towards non-macrophagic cell lines. This binding triggers Ca2+-based signalling responses in the target cell while providing an anchor for the invading parasite. Accordingly, exogenous addition of either TSSA-derived peptides or specific antibodies significantly inhibits invasion of CL Brener, but not Sylvio X-10, trypomastigotes. Non-infective epimastigote forms, which do not express detectable levels of TSSA, were stably transfected with TSSA cDNA from either parasite stock. Although both transfectants produced a surface-associated mucin-like TSSA product, epimastigotes expressing CL Brener TSSA showed a similar to 2-fold increase in their attachment to mammalian cells. Overall, these findings indicate that CL Brener TSSA functions as a parasite adhesin, engaging surface receptor(s) and inducing signalling pathways on the host cell as a prerequisite for parasite internalization. More importantly, the contrasting functional features of TSSA isoforms provide one appealing mechanism underlying the differential infectivity of T. cruzi stocks.
Resumo:
Toxosplasma gondii is the model parasite of the phylum Apicomplexa, which contains numerous obligate intracellular parasites of medical and veterinary importance, including Eimeria, Sarcocystis, Cryptosporidium, Cyclospora, and Plasmodium species. Members of this phylum actively enter host cells by a multistep process with the help of microneme protein (MIC) complexes that play important roles in motility, host cell attachment, moving junction formation, and invasion. T. gondii (Tg)MIC1-4-6 complex is the most extensively investigated microneme complex, which contributes to host cell recognition and attachment via the action of TgMIC1, a sialic acid-binding adhesin. Here, we report the structure of TgMIC4 and reveal its carbohydrate-binding specificity to a variety of galactose-containing carbohydrate ligands. The lectin is composed of six apple domains in which the fifth domain displays a potent galactose-binding activity, and which is cleaved from the complex during parasite invasion. We propose that galactose recognition by TgMIC4 may compromise host protection from galectin-mediated activation of the host immune system.
Resumo:
This cross-sectional and descriptive study aimed to verify the adherence of patients with Bipolar Affective Disorder (BAD) to medication and to identify possible causes of adherence and non-adherence to medication according to the pharmacotherapeutic profile. The study was carried out in a mental health service in a city in the interior of the state of Sao Paulo. Participants included 101 patients with BAD. Structured interviews and the Morisky-Green test were used for data collection, and the Statistical Package for Social Science was employed for data analysis. Most subjects (63%) did not adhere to medication. Although there were no significant differences between the adherent and non-adherent groups for the researched variables, the use of polypharmacotherapy and complex treatment regimens was observed in treatment for BAD. In practice, implementing strategies to improve the adherence of patients to medication treatment remains a challenge.
Resumo:
Successful international clones have recently emerged among Escherichia coli that produce CTX-M beta-lactamases as important causes of community-onset urinary tract and bloodstream infections. One hundred and seven isolates that belong to sequence types (STs) ST38, ST131, ST405, ST648, and 38 nonrelated CTX-M producing E. coli from Canada and the Netherlands were assigned to phylogenetic groups and tested for the presence of genes encoding for virulence factors (VFs) using established multiplex polymerase chain reaction. The STs E. coli were significantly more resistant to antibiotics-ST38, ST405, and ST648 belonged to phylogenetic group D while ST131 belonged to B2. Secreted autotransporter toxin (sat), aerobactin receptor, and pathogenicity island marker were significantly more common among the STs; the heat-resistant agglutinin (hra) was present in ST38, sat, and uropathogenic-specific protein, and putative adhesin-siderophore receptor was more common in ST131, while outer membrane protease T was present in ST648. ST131 had a significantly higher VF score. In conclusion, the precise role of these VFs remains to be elucidated; however, we have identified certain putative VFs that possibly contribute to the fitness and success of certain sequence types. (C) 2012 Elsevier Inc. All rights reserved.
Resumo:
Abstract Background Leptospirosis is considered a re-emerging infectious disease caused by pathogenic spirochaetes of the genus Leptospira. Pathogenic leptospires have the ability to survive and disseminate to multiple organs after penetrating the host. Leptospires were shown to express surface proteins that interact with the extracellular matrix (ECM) and to plasminogen (PLG). This study examined the interaction of two putative leptospiral proteins with laminin, collagen Type I, collagen Type IV, cellular fibronectin, plasma fibronectin, PLG, factor H and C4bp. Results We show that two leptospiral proteins encoded by LIC11834 and LIC12253 genes interact with laminin in a dose - dependent and saturable mode, with dissociation equilibrium constants (KD) of 367.5 and 415.4 nM, respectively. These proteins were named Lsa33 and Lsa25 (Leptospiral surface adhesin) for LIC11834 and LIC12253, respectively. Metaperiodate - treated laminin reduced Lsa25 - laminin interaction, suggesting that sugar moieties of this ligand participate in this interaction. The Lsa33 is also PLG - binding receptor, with a KD of 23.53 nM, capable of generating plasmin in the presence of an activator. Although in a weak manner, both proteins interact with C4bp, a regulator of complement classical route. In silico analysis together with proteinase K and immunoflorescence data suggest that these proteins might be surface exposed. Moreover, the recombinant proteins partially inhibited leptospiral adherence to immobilized laminin and PLG. Conclusions We believe that these multifunctional proteins have the potential to participate in the interaction of leptospires to hosts by mediating adhesion and by helping the bacteria to escape the immune system and to overcome tissue barriers. To our knowledge, Lsa33 is the first leptospiral protein described to date with the capability of binding laminin, PLG and C4bp in vitro.
Resumo:
OBJETIVO: Descrever e comparar os escores de adesão às precauções padrão (PP) de profissionais de enfermagem que atuavam nas unidades de internação de um hospital universitário do Estado de São Paulo. MÉTODOS: Trata-se de estudo quantitativo transversal, comparativo, com a aplicação da escala psicométrica de adesão às PP, desenvolvido por Gershon et al. (1995), traduzida e validada por Brevidelli e Cianciarullo (2009), entre primeiro de setembro de 2009 e 31 de março de 2010, com 256 profissionais de enfermagem. RESULTADOS: Evidenciou-se que 152 (59,4%) profissionais apresentaram escores médios altos para a adesão às PP, igual ou acima de 4,5; 98 (38,3%) escores intermediários, entre 3,5 e 4,49 e 6 (2,3%) baixos, ou seja, menor que 3,5. CONCLUSÕES: Não houve diferenças estatisticamente significativas entre os escores e outras variáveis, entretanto, destacou-se a importância do resultado positivo encontrado pela valorização das ações de educação permanente pela instituição.
Resumo:
OBJETIVO: Identificar, na perspectiva da pessoa com esquizofrenia e de seu familiar, como ocorre a interação paciente-familiar relacionada à adesão ao tratamento medicamentoso. MÉTODOS: Estudo de abordagem qualitativa, com referencial metodológico da Teoria Fundamentada nos Dados e pressupostos do Interacionismo Simbólico. Participaram do estudo 36 pessoas com esquizofrenia em tratamento ambulatorial e 36 familiares. Para obtenção dos dados, usadas a entrevista gravada e a observação. RESULTADOS: Os depoimentos obtidos revelaram que familiares podem fornecer apoio e motivação, propiciando a adesão do paciente ao tratamento, podendo também incentivá-lo a não aderir à farmacoterapia. Destacaram-se ainda a influência da sobrecarga e o despreparo do familiar cuidador sobre a qualidade dos cuidados prestados. CONCLUSÃO: Profissionais da saúde podem intervir junto aos familiares, encorajando as interações que colaboram com o sucesso do tratamento e incentivando-os a modificar as interações que o comprometem.